640837694 has 8 divisors (see below), whose sum is σ = 1098578928. Its totient is φ = 274644720.

The previous prime is 640837663. The next prime is 640837709. The reversal of 640837694 is 496738046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22887047 + ... + 22887074.

It is an arithmetic number, because the mean of its divisors is an integer number (137322366).

Almost surely, 2^640837694 is an apocalyptic number.

640837694 is a deficient number, since it is larger than the sum of its proper divisors (457741234).

640837694 is a wasteful number, since it uses less digits than its factorization.

640837694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45774130.

The product of its (nonzero) digits is 870912, while the sum is 47.

The square root of 640837694 is about 25314.7722486299. The cubic root of 640837694 is about 862.1497031319.

The spelling of 640837694 in words is "six hundred forty million, eight hundred thirty-seven thousand, six hundred ninety-four".